1. Field of the Invention
This invention involves a squeegee blade as used in screen process printing, and, more particularly, a squeegee blade having an ink-holding cavity profile with the cavity located immediately in front of the contact edge of the squeegee blade.
2. Description of the Prior Art
For the past one hundred years, the squeegee used for screen process printing (also known as silk screen printing) has utilized a flat rectangular blade with a sharp contact edge. Some progress has been made in providing squeegee blades made of sophisticated plastics and synthetic rubber having varying hardnesses, the desirability of their use depending on the particular ink used or substrate printed. The squeegee blade, when placed in a holder, has continued to be the accepted tool to move ink across a screen fabric and stencil surface to produce print impressions.
The squeegee characteristically is drawn at a forward angle across the surface of the screen fabric. The forward movement of the tilted conventional squeegee blade across the surface of the screen fabric moves the ink directly ahead of its contact edge. As stencil openings are contacted through the screen fabric, ink is deposited upon the substrate. Should few or no openings in the stencil be present, the ink eventually would be dispersed out past the ends of the squeegee blade, that being the avenue of lesser resistance as the squeegee blade moves forward There are significant shortcomings in the conventional squeegee blade operation, including lack of control of the ink supply, wear of the screen fabric, operator fatigue, and lack of efficiency.
The objectives of the present profile squeegee blade invention are:
1. Better print quality by improved control of ink supply and feed to the substrate; PA1 2. Reduction in screen fabric wear; PA1 3. Reduction in squeegee effort, particularly reduction in fatigue on long hand runs and large surfaces; PA1 4. Action of the squeegee blade as a scraper rather than a tool for forcing ink through the screen fabric, thereby reducing squeegee wear; PA1 5. Reduction in downtime due to screen fabric clogging caused by varying squeegee blade pressure; PA1 6. Variability of profile design to accomodate various inks and substrates; and PA1 7. Application to both hand and machine operations.